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Genetic regulation of differentiation in Physarum polycephalum

Published online by Cambridge University Press:  14 April 2009

N. K. Honey
Affiliation:
Department of Biochemistry, University of Otago, Dunedin, New Zealand
R. T. M. Poulter
Affiliation:
Department of Biochemistry, University of Otago, Dunedin, New Zealand
D. M. Teale
Affiliation:
Department of Zoology, University of Otago, Dunedin, New Zealand
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Plasmodial formation in the Myxomycete Physarum polycephalum is controlled by a mating type (mt) locus. There are a number of different heterothallic mt alleles; and also a variant, mth, that allows plasmodial formation in pure clones. This paper reports an analysis of this differentiation system. The strain CL (mth) forms plasmodia in pure clones (i.e. it selfs). CL was mutagenized with NMG and 21 mutants unable to differentiate into amoebae were isolated. The mutants, together with CLd, fell into two complementation groups, twelve in difA and ten in difB. Both complementation groups are closely linked or allelic to the mt locus. difA represents a gene essential for plasmoclial formation, but it is suggested that difB represents a class of revertants to the mt2 heterothallic state. A model of the control of plasmodial formation is proposed in which the mt locus is suggested to code for the repressor of the difA gene. Genetic control is explained in terms of the dilution of allele-specific repressors.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1979

References

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